Signal mastarm bracket assembly

ABSTRACT

A universal mastarm bracket assembly for mounting traffic signal lights, signs or other information portraying or signaling devices on mastarms, the bracket including an elongated member having a surface thereon adapted for engagement with the signal light, sign or other structure to be supported, mastarm clamp means slidably engageable with the elongated member over its length, and adjustably securable at a selected location therealong, and at least one variable length chain connected to said mastarm clamp means for extending around, and frictionally engaging, a mastarm.

United States Patent 1 91 Parduhn Dec. 17, 1974 [54] SIGNAL MASTARM BRACKET ASSEMBLY 2,808,218 10/1957 Steller 248/295 X 2,942,366 6/1960 Pfaff et al. [76] inventor Alfred f BOX 3,586,280 6/1971 Parduhn 248/230 x Oklahoma clty, Okla- 73114 3,764,099 10/1973 Parduhn 248/230 x [22] Filed: Aug. 20, 1973 Primary Examiner-J. Franklm Foss [21] Appl' 389,943 Attorney, Agent, or Firm-William R. Laney Related US. Application Data [63] Continuationimpart of Ser. No. 231,131, March 2, [57] ABSTRACT 1972, Pat. No. 3,764,099. A universal mastarm bracket assembly for mounting traffic signal lights, signs or other information portray- [52] US. Cl 248/214, 40/125 N, 116/63 R, g or signaling devices on mastarms, the bracket 248/231, 340/119 cluding an elongated member having a surface [51] Int. Cl. Fl6m 13/02 th r n adapt d for engagement with-the signal g 158] Field of Search 248/214, 230, 231, 295, s gn or th r str to be pp mastarm 248/286, 221; 40/125 1-1, 125 N; 116/63 R, clamp means slidably engageable with the elongated 116/DIG, 16; 52/40; 340/119 member over its length, and adjustably securable at a selected location therealong, and at least one variable [56] Referenc Cit d length chain connected to said mastarm clamp means UNITED STATES PATENTS for extending around, and frictionally engaging, a 2,634,939v 4/1953 Voss 248/231 mastarm 2,754,944 7/1956 Petersen 248/231 X 13 Claims, 4 Drawing Figures SIGNAL MASTARM BRACKET ASSEMBLY RELATED PATENT APPLICATION This application is a continuation-in-part of my US. Pat. application 231,131, filed Mar. 2, 1972, and entitled Signal Mastarm Bracket, now US. Pat. No. 3,764,099.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to universal bracket structures suitable for mounting and supporting traffic signal lights, signs and other fixtures on horizontally or vertically extending supporting structures, such as mastarms or vertical stanchions, with the brackets permitting adjustability of the angular and vertical. positions of the supported fixture, sign or signal light. a

2. Brief Description of the Prior Art In my U.S. Pat. No. 3,586,280, I disclose a mastarm bracket by which traffic signal lights and other fixtures mounting member at a selected location thcrealong.

Movable joint means is secured to the track engaging means and projects from the track engaging means in a direction substantially normal to the longitudinal axis of said elongated mounting member, the movable joint means including a first tubular section, and a second tubular section telescopingly engaging the first tubular section for rotation on the first tubular section about an axis extending through, and common to,'the first and second tubular sections.

may be mounted on a mastarm so that the fixtures may my co-pending US. Pat. application No. 231,131

where a chain structure is employed for direct engagement with a mastarm, and where the structure which supports the signal light, sign or other device mounted by the use of the mastarm bracket is threaded at its opposite ends, 'so that the size of the traffic signal light or other structure which is to besupported by the mastarm bracket can vary widely, and the bracket supporting capability can be adjusted to such variation in size.

BRIEF DESCRIPTION OF THE PRESENT- INVENTION The present invention constitutes yet a further improvement for certain types of uses of signal mastarm brackets, and particularly provides certain improvements in the chain clamping structure used for extending flexible chains around mastarms of varying diametric sizes or peripheral configurations. The structure also is further improved in that the portion of the mastarm bracket which is utilized for engaging the elongated structural member upon which'the sign or signal light is mounted is adapted to slidably engage such elongated structural member in such a way that the bolts used for interlocking the elongated structural member with the clamp means are readily accessible, and so that an l-beam supporting member can be employed usefully, particularly in the case of signs or signal light structures having a substantially monoplanar mounting surface which can be flatly abutted against the flange of the I-beam member.

Broadly described, the present invention comprises a simple, economically constructed mastarm bracket assembly which includes an elongated mounting member having track means formed thereon and adapted to The mastarm bracket assembly of the invention further includes means for selectively securing the second tubular section against rotation on the firsttubular section at a desired point in the course of one complete revolution about said first tubular section, and a clamp plate secured to the second tubular section for rotation therewith when said second tubular section is rotated on the first tubular sectiomThe clamp plate preferably is formed with one of its sides secured to the second tubular section and the opposite side of dished, arcuate configuration. Pairs of bifurcated ears are positioned on the clamp plate at the corners thereof, and are adapted for the securement of the ends of elongated flexible chains in the bifurcations in the ears.

The described structure facilitates the mounting of a traffic signal light, sign or other structure on vertical, horizontal or angular mastarms in such way that the signal light or sign can be pivoted in three planes so that its exposure can be adjusted to meet the needs of oncoming pedestrian or vehicular traffic.

An important object of the present invention is to provide a mastarm bracket assembly which can be moved or pivoted in three different planes, and thus achieves substantially universal adjustability, and constructed so that traffic signal heads or signs of various types may be quickly and securely fastened on a supporting structure forming part of the assembly.

Another object of the invention is to provide a mastarm bracket assembly by which heavy fixtures, such as traffic signal lights or heavy signs, may be secured to a mastarm of substantially any geometric cross-sectional configuration or any diameter.

An additional object of the invention is to provide a mastarm bracket assembly which can be quickly and easily assembled by relatively unskilled personnel, and which is rugged in construction and has a long and trouble free service life.

Another object of the present invention is to provide a mastarm bracket assembly useful for supporting traffic signal lights or signs carrying indicia thereon on either a vertical mastarm or stanchion or on a horizontally extending mastarm.

Another object of the invention is to provide a mastarm bracket assembly for mountingsignal lights or signs on horizontally or vertically extending mastarms by the use of simple hand tools, and without the requirement of special skills or knowledge on the part of the personnel effecting such mounting.

Additional objects and advantages of the invention will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view of the vertical column, mastarm and mastarm bracket assembly of the present invention with a traffic signal sign supported thereby.

FIG. 2 is a side elevation view of the mastarm bracket assembly of the present invention as it is utilized for supporting a traffic signal sign, and showing the mastarm upon which it is mounted in section.

FIG. 3 is a perspective view of the mastarm bracket assembly of the present invention as it appears when mounted on a horizontally extending mastarm.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Referring initially to FIG. 1, shown therein is a signal sign mounted on a mastarm structure by'a mastarm bracket assembly constructed in accordance with the present invention. The vertically extending pole or stanchion has a horizontally extending mastarm 12 mounted near the upper end thereof in conventional fashion. Secured to the mastarm 12 by means of the mastarm bracket assembly 14 of the present invention is a sign l6 depicting certain indicia used in traffic control.

The mastarm bracket assembly 14 of the invention includes an elongated mounting member 18 which, in the portrayed use of the bracket assembly, extends vertically, although, as will hereinafter be explained, the elongated mounting member can, in some usages of the device, extend horizontally. The elongated mounting member 18 is, in the illustrated embodiment, an I-beam structure having a facing flange 20 having a plurality of bolt apertures 22 formed therein and connected through a web plate 24 to a C-shaped edge channel 26.

The C-shaped edge channel 26 and the facing flange 20 define with the web plate 24, a pair of tracks disposed on opposite sides of the web plate 24 and extending longitudinally therealong.

The mastarm bracket assembly 14 further includes a track engaging means 28 which is of C-shaped crosssectional configuration, and includes a base plate 30, a pair of side plates 32 and 34 and a pair of opposed, spaced flanges 36 and 38. As the track engaging means 28 is utilized cooperatively with the elongated mounting member 18, it will be perceived that the flanges 36 and 38 are positioned on opposite sides of the web plate 24, and in the track defined by the web plate in cooperation with the facing flange 20 and the C-shaped edge channel 26. The slot defined between the flanges 36 and 38 of the track engaging means 28 is of sufficient width to accommodate the web plate 24. In addition, at spaced intervals along the slot between the flanges 36 and 38, there are formed generally circular openings 39 of greater diameter than the width of the slot between the flanges, with portions of these openings being visible in FIG. 3 of the drawing. Positioned opposite the openings and located in the base plate are a plurality of bolt apertures to accommodate the shanks of bolts or other suitable clamping means utilized for the purpose of the clamping or fastening the track engaging means 28 to the elongated mounting member 18 at a selected location therealong in a manner and for a purpose hereinafter described.

Welded or otherwise suitably secured to the track engaging means 28 is the movable joint means designated generally by reference numeral 40. In the illustrated embodiment of the invention, the movable joint means includes a first tubular section 41 and a second tubular section 42 which telescopingly and threadedly engages the first tubular member. Means, such as a set screw 43, is provided for selectively securing the second tubular member 42 against rotation on the first tubular member 41 at a selected position thereon. Secured to the end of the second tubular section 42 opposite its end which engages the first tubular section 41 is a clamp plate 46.

The clamp plate 46 projects in a direction substantially normal to thecommon axis of the first and second tubular sections, and is characterized in having bifurcated ears 48, 50 and 56 disposed at three corners thereof, and a similar-bifurcated ear located at the fourth, unseen corner thereof. The bifurcated ear 48 is provided with a slot therein for receiving the shank of ration, and its arcuate surface accommodates it to fitting against the side of va cylindrical mastarm in the manner depicted in FIG. 2.

For the purpose of securing the clamp plate 46 to the mastarm, a pair of flexible chains 60 and 62 are provided. The chains 60 and 62 are of the type which can be varied in length by adding or removing links therefrom. One endof the chain 60 has a pin extended through its end link for pinning the chain to the bifurcated ear 56. The other end of this chain, when it is used for securing the structure of the invention to 'a mastarm, has a bolt 67 pivotally connected to the end link of the chain and passed through a friction block 68 which has a semi-cylindrical surface adapted to maintain the friction block in engagement with the mating concave back side of the bifurcated ear 48. A tightening nut 70 is threaded on the bolt 67 and is used for tensioning the chain around the mastarm l2. Theconstruction of the chain 62 and the manner in which it is secured to the clamp plate 46 by means of the ears 50 is identical to the construction and manner of securement of the chain 60.

In assembling the mastarm bracket assembly of the invention, the elongated mounting member 13 is first slidingly engaged by the track engaging means 28. In effecting this engagement, bolts are first passed through the circular openings formed between the flanges 36 and 38 so that the bolt shanks project,

through the aligned openings formed in the base plate 30 of the track engaging means. Bolts of substantial length can be positioned in this matter so that the heads of such bolts are located within the C-shaped crosssectional elongated member forming the track engaging means. With the bolts so positioned, they may then be positioned by manipulation of the shank portion projecting through the base plate 30 so that the heads of the bolts are caused to pass into the interior channel formed within the C-shaped edge channel 26 of the elongated mounting member 18 when this mounting member is slid longitudinally with respect to the track engaging means 28 with the C-shaped edge channel enclosed within the interior of the C-shaped crosssectional configuration of the elongated member forming the track-engaging means. The heads of the bolts are then positioned within the interior of the C-shaped edge channel 26 in the manner depicted in FIG. 4. Nuts can then be threaded on the ends of bolts so as to facilitate the effective tightening of the nuts at a time when the elongated mounting member 18 is moved upwardly or downwardly within the track engaging means 28 to the position desired. It will be perceived that the nuts ing means at the locations where the shanks of the bolts project through the base plate 30 of the track engaging means 28.

in the utilization of the mastarm bracket assembly of the invention, the bracket assembly is first mounted on a mastarm by means of the chains 60 and 62. As a result of the flexibility of these chains and their capability of being easily lengthened or shortened, the bracket assembly can be mounted on mastarms, spars, stanchions or other supporting structures of various diametric sizes, or even having peripheral geometries which depart from the cylindrical form of the mastarm 12 depicted in FIG. 1. The chains 60 and 62 can be quickly and easily attached to the bifurcated ears 48 and 50 at the corners of the clamp plate 46, and canbe tightened easily by the use of a conventional wrench applied to the nuts 70. The first tubular section 41 and second tubular section 42 can be rotated relative to each other until the. track engaging means 28 and the elongated mounting member 18 which it engages extends at-a desired angle for properly displaying a sign or signal to oncoming pedestrian or vehicular traffic which is to observe indicia orsignals portrayed by such sign or signal light mounted by means of the mastarm bracket assembly.

Although a preferred embodiment of the invention has been herein described in order to afford an example-of its practice to those skilled in the art, it will be understood that various changes and innovations in the described structure can be effected without departure from the basic principles underlying the invention.

' Changes and innovations of this type are therefore intended to be circumscribed by the spirit and scope of the invention, except as the same maybe necessarily limited by the appended claims or reasonable equivalents thereof.

What is claimed is: l. A mastarm bracket assembly comprising: an elongated mounting member adapted to supportingly receive a structure for providing a visual display of indicia; track means on said elongated member; track engaging means slidingly engaging said track means for sliding movement longitudinally along said elongated mounting member; means for clamping the track means to the track engaging means to arrest the sliding movement of the track engaging means along the track means at a 1 selected location therealong;

. are easily accessible at the rear side of the track engagmovable joint means secured to said track engaging means and projecting from the track engaging means in a direction substantially normal to the longitudinal axis of said elongated mounting member, said joint means including;

a first tubular section; and

a second tubular section telescopingly engaging the first tubular section for rotation on the first tubular section about an axis extending through, and common to, the first and second tubular sections;

means for selectively securing the second tubular section against rotation on the first tubular section at a desired point in the course of one complete rotation about said first tubular section; v

a clamp plate secured to the end of said second tubular section opposite its end telescopingly engaged with the first tubular section;

at least one elongated flexible element having one end secured to said clamp plate; and

means for detachably securing the other end of said elongated flexible element to said clamp plate.

2. A mastarm bracket assembly as defined in claim 1 wherein said clamp plate has one side of dished, arcu ate configuration and further is provided with a plurality of spaced, bifurcated ears for securing said flexible element to said plate.

3. A mastarm bracket assembly as defined in claim 1 wherein said elongated mounting member is of I- shaped cross-sectional configuration and includes a web section having said track means on-opposite sides thereof.

4. A mastarm bracket assembly as defined in claim 1 wherein said elongated mounting member further includes;

a facing flange extending normal to said web section along one edge thereof; and

a C-shaped edge channel extending along the opposite edge of said web section from said facing flange.

5. A mastarm bracket assembly as defined in claim 1 wherein said track engaging means is an elongated member of C-shaped cross-sectional configuration having;

a base plate bearing against said elongated mounting member; and

a pair of side plates projecting on opposite sides of said elongated mounting member for sliding movement therealong.

6. A mastarm bracket assembly as defined in claim 2 wherein said clamp plate is generally rectangular in configuration and has one of said bifurcated cars at each corner thereof, two of said ears along'one edge of said plate each having a concavity on the rear sid thereof;

and wherein there are two of said flexible elements, and said means for detachably securing the other end of each of said elongated flexible elements to said clamp plate comprises; a securing bolt secured to said other end of each of said flexible elements; j v a friction block slidingly receiving therethr ough, the shank of one of said securing bolts and mating with, and positioned in, the-concavity of the rear side one of said bifurcated ears; and a nut threaded on the shank of each of said securing bolts and bearing against said friction block.

7. A mastarm bracket assembly as defined in claim wherein said track engaging means elongated member is further characterized in having a pair of spaced, opposed flanges projecting toward each other from said side plates, and defining therebetween a slot extending along the length of said elongated member of C-shaped cross-sectional configuration, said spaced opposed flanges further having a plurality of spaced, generally circular openings formed through the flanges and bisected by said slot; and

wherein said base plate has a plurality of spaced openings therein aligned with said generally circular openings whereby bolts having a greater length than the distance between said base plate and said spaced, opposed flanges can be extended through said generally circular openings, and through the aligned openings in said base plate to position the head of the bolts within the interior of said elongated member of C-shaped cross-sectional configuration constituting said track engaging means.

8. A mastarm bracket assembly as defined in claim 7 wherein said C'shaped edge channel is further characterized in having spaced, opposed projecting toward each other and extending substantially parallel to the base plate of theelongated member of said track engaging means and parallel to the spaced, opposed flanges of the elongated member of such trackengaging means; and

wherein said mastarm bracket assembly is further characterized in having a plurality of bolts having heads positioned within said C-shaped edge channel, with the shank of said bolts projecting between -said spaced, opposed flanges of said C-shaped edged channel and through the spaced openings in the base plate of said elongated member forming said track engaging means; and

nuts threaded on the shanks of said'bolts to releasably retain said track engaging means in engagement with said C-shaped edge channel.

9. A mastarm bracket assembly as defined in claim 8 wherein said clamp plate is generally rectangular in configuration and has one of said bifurcated ears at eachc'orner thereof, two of said ears along one edge of said plate each having a concavity on the rear side thereof;

and wherein there are two of said flexible elements, and said means for detachably securing the other end of each of said elongated flexible elements to said clamp plate comprises;

a securing bolt secured to said other end of each of said flexible elements;

a friction block slidingly receiving therethrough, the shank of one of said securing bolts and mating with,

and positioned in, the concavity on the rearside of one of said bifurcated ears; and

a nut threaded on the shank of each of said securing bolts and bearing against said friction block.

10. A universal mastarm bracket assembly comprising:

nally along said elongated mounting member;

means for selectively securing said engaging means to said mounting member at a selected location along the length thereof;

moveable joint means secured to said engaging means and projecting from the engaging means in a direction substantially normal to the longitudinal axis of said elongated mounting member, said joint means including:

a first tubular section; and

a second tubular section telescopingly engaging the second tubular section for rotation on the first tubular section about an axis extending through, and common to, the first and second tubular sections;

means for selectively securing the second tubular section against rotation on the first tubular section .at a desired point in the course of one complete rotation about said first tubular section;

a clamp plate secured to the end-of said second tubular section opposite its end telescopingly engaged with said first tubular section, said clamp having a concave side disposed on the opposite side thereof from its side secured to said second tubular section for general mating engagement with the cylindrical surface of a mast arm; and

means detachably secured to said clamp plate and extendable around a mast arm for drawing said clamp plate into engagement with said mast arm.

11. A universal mastarm bracket assembly as defined in claim 10 wherein said engaging means comprises an elongated member of C-shaped cross sectional configuration including:

a base plate; and a pair of side plates extending along opposite sides of said elongated mounting member for tracking along said elongated mounting member during the sliding movement of said engaging means on said elongated mounted member. .12. A universal mastarm bracket assembly as defined in claim 10 I 1 wherein said clamp plate is configured to provide a surface of generally semi-cylindrical configuration for mating with a portion of a cylindrical mastarm; and wherein said means detachably secured to said clampplate comprises: first means extendable around a mastarm and having one end detachably connected to one side edge of said clamp plate, and a second end detachably connected to a second side edge of said clamp plate; and second means extendable around a mastarm and having one end detachably connected to said one side edge of said clamp plate and a. second end detachably connected to a second side edge of said clamp plate.

13. A universal mastarm bracket assembly as defined in claim 12 wherein said clamp plate is rectangular in configuration and said mastarm bracket assembly is further characterized in including means at each corner of the plate facilitating detachable connection to the clamp plate of the ends of the first and second means extendable around a mastarm. 

1. A mastarm bracket assembly comprising: an elongated mounting member adapted to supportingly receive a structure for providing a visual display of indicia; track means on said elongated member; track engaging means slidingly engaging said track means for sliding movement longitudinally along said elongated mounting member; means for clamping the track means to the track engaging means to arrest the sliding movement of the track engaging means along the track means at a selected location therealong; movable joint means secured to said track engaging means and projecting from the track engaging means in a direction substantially normal to the longitudinal axis of said elongated mounting member, said joint means including; a first tubular section; and a second tubular section telescopingly engaging the first tubular section for rotation on the first tubular section about an axis extending through, and common to, the first and second tubular sections; means for selectively securing the second tubular section against rotation on the first tubular section at a desired point in the course of one complete rotation about said first tubular section; a clamp plate secured to the end of said second tubular section opposite its end telescopingly engaged with the first tubular section; at least one elongated flexible element having one end secured to said clamp plate; and means for detachably securing the other end of said elongated flexible element to said clamp plate.
 2. A mastarm bracket assembly as defined in claim 1 wherein said clamp plate has one side of dished, arcuate configuration and further is provided with a plurality of spaced, bifurcated ears for securing said flexible element to said plate.
 3. A mastarm bracket assembly as defined in claim 1 wherein said elongated mounting member is of I-shaped cross-sectional configuration and includes a web section having said track means on opposite sides thereof.
 4. A mastarm bracket assembly as defined in claim 1 wherein said elongated mounting member further includes; a facing flange extending normal to said web section along one edge thereof; and a C-shaped edge channel extending along the opposite edge of said web section from said facing flange.
 5. A mastarm bracket assembly as defined in claim 1 wherein said track engaging means is an elongated member of C-shaped cross-sectional configuration having; a base plate bearing against said elongated mounting member; and a pair of Side plates projecting on opposite sides of said elongated mounting member for sliding movement therealong.
 6. A mastarm bracket assembly as defined in claim 2 wherein said clamp plate is generally rectangular in configuration and has one of said bifurcated ears at each corner thereof, two of said ears along one edge of said plate each having a concavity on the rear side thereof; and wherein there are two of said flexible elements, and said means for detachably securing the other end of each of said elongated flexible elements to said clamp plate comprises; a securing bolt secured to said other end of each of said flexible elements; a friction block slidingly receiving therethrough, the shank of one of said securing bolts and mating with, and positioned in, the concavity of the rear side of one of said bifurcated ears; and a nut threaded on the shank of each of said securing bolts and bearing against said friction block.
 7. A mastarm bracket assembly as defined in claim 5 wherein said track engaging means elongated member is further characterized in having a pair of spaced, opposed flanges projecting toward each other from said side plates, and defining therebetween a slot extending along the length of said elongated member of C-shaped cross-sectional configuration, said spaced opposed flanges further having a plurality of spaced, generally circular openings formed through the flanges and bisected by said slot; and wherein said base plate has a plurality of spaced openings therein aligned with said generally circular openings whereby bolts having a greater length than the distance between said base plate and said spaced, opposed flanges can be extended through said generally circular openings, and through the aligned openings in said base plate to position the head of the bolts within the interior of said elongated member of C-shaped cross-sectional configuration constituting said track engaging means.
 8. A mastarm bracket assembly as defined in claim 7 wherein said C-shaped edge channel is further characterized in having spaced, opposed projecting toward each other and extending substantially parallel to the base plate of the elongated member of said track engaging means and parallel to the spaced, opposed flanges of the elongated member of such track engaging means; and wherein said mastarm bracket assembly is further characterized in having a plurality of bolts having heads positioned within said C-shaped edge channel, with the shank of said bolts projecting between said spaced, opposed flanges of said C-shaped edged channel and through the spaced openings in the base plate of said elongated member forming said track engaging means; and nuts threaded on the shanks of said bolts to releasably retain said track engaging means in engagement with said C-shaped edge channel.
 9. A mastarm bracket assembly as defined in claim 8 wherein said clamp plate is generally rectangular in configuration and has one of said bifurcated ears at each corner thereof, two of said ears along one edge of said plate each having a concavity on the rear side thereof; and wherein there are two of said flexible elements, and said means for detachably securing the other end of each of said elongated flexible elements to said clamp plate comprises; a securing bolt secured to said other end of each of said flexible elements; a friction block slidingly receiving therethrough, the shank of one of said securing bolts and mating with, and positioned in, the concavity on the rear side of one of said bifurcated ears; and a nut threaded on the shank of each of said securing bolts and bearing against said friction block.
 10. A universal mastarm bracket assembly comprising: an elongated mounting member mounted to supportingly receive a structure for providing a visual display of indicia; engaging means slidingly engaging said elongated mounting member for sliding movement longitudinally along said elongateD mounting member; means for selectively securing said engaging means to said mounting member at a selected location along the length thereof; moveable joint means secured to said engaging means and projecting from the engaging means in a direction substantially normal to the longitudinal axis of said elongated mounting member, said joint means including: a first tubular section; and a second tubular section telescopingly engaging the second tubular section for rotation on the first tubular section about an axis extending through, and common to, the first and second tubular sections; means for selectively securing the second tubular section against rotation on the first tubular section at a desired point in the course of one complete rotation about said first tubular section; a clamp plate secured to the end of said second tubular section opposite its end telescopingly engaged with said first tubular section, said clamp having a concave side disposed on the opposite side thereof from its side secured to said second tubular section for general mating engagement with the cylindrical surface of a mast arm; and means detachably secured to said clamp plate and extendable around a mast arm for drawing said clamp plate into engagement with said mast arm.
 11. A universal mastarm bracket assembly as defined in claim 10 wherein said engaging means comprises an elongated member of C-shaped cross sectional configuration including: a base plate; and a pair of side plates extending along opposite sides of said elongated mounting member for tracking along said elongated mounting member during the sliding movement of said engaging means on said elongated mounted member.
 12. A universal mastarm bracket assembly as defined in claim 10 wherein said clamp plate is configured to provide a surface of generally semi-cylindrical configuration for mating with a portion of a cylindrical mastarm; and wherein said means detachably secured to said clampplate comprises: first means extendable around a mastarm and having one end detachably connected to one side edge of said clamp plate, and a second end detachably connected to a second side edge of said clamp plate; and second means extendable around a mastarm and having one end detachably connected to said one side edge of said clamp plate and a second end detachably connected to a second side edge of said clamp plate.
 13. A universal mastarm bracket assembly as defined in claim 12 wherein said clamp plate is rectangular in configuration and said mastarm bracket assembly is further characterized in including means at each corner of the plate facilitating detachable connection to the clamp plate of the ends of the first and second means extendable around a mastarm. 